Electric circuit breaker



y 1947 s. R. SMI TH, JR

ELECTRIC CIRCUIT BREAKER 2 Sheets-Sheet 2 Filed May 11, 1940 a 0 Z J 4 4 w m M w 6 1 p W n z u I flwn wmmmmwmd mn i s o o g n 4 t t .l U b P a a 4 e 6 0 m u m v s K 0 H .24. v n y (l 1 4MH I e H H m w n n n u S w 5 an a Q n P u c u 7 M. J w u 1 n n aux n 1 n 4 w w a M H a a H H go I l 4. I Al u 6x 3 F Illll J1 z n w m a a a Patented July 15, 1947 nuac'rmc cmcurr enema Sidney R. Smith, Jr., Pittsfleld, Mala, auignor to General Electric Company, a corporation of New York Application May 11, 1940, Serial No. 834,629

39 Claims. -1

My invention relates to electric circuit breakers and more particularly to such circuit breakers which are adapted for use in place of the conventional fuse cutout devices.

Fuse cutout devices have been used to a large extent in the protection of high-tension electric circuits. Devices of this type in general comprise replaceable fusible means mounted within a. suitable holder and they are usually located in close proximity to the high-tension conductors 'as a consequence of which they are relatively inaccessible for inspection and maintenance. Dimculties have been encountered in providing cutouts having an electric fuse convenient for installation and inspection and, at the same time, capable of being removable and replaceable. In any event, an abnormal electrical condition occurring on a circuit,protected by a fuse cutout will destroy the fuse and, hence, require replacement thereof. Aiuwzg'h recent experimentation and research have educed the cost of the replaceable elements,

nevertheless such cost is still appreciable and it be desirable to provide a fuseless cutout which will automatically interrupt the circuit unde abnormal electrical conditions and yet wherein it is unnecessary to replace any elements after the protective operation of such cutouts as is necessary with the fuse cutouts of the prior art.

It is an object of my invention, therefore, to provide a new and improved circuit breaker adapted to replace the fuse cutouts of the prior art.

It is another object of my invention to provide a new and improved fuseless cutout which is simple and compact and which may be used in connection with the prior-art holders for fuse cutouts.

It is a further object of my invention to provide a fuseless cutout for protecting electrical apparatus which is simple, compact, and economical in construction, and which, at the same time, gives an immediate and reliable indication of the actuation and condition of the protecting device.

Still another object of my invention is to provide a fuseless cutout which is rugged, compact, and strong in construction, dependable in operation, and well adapted to meet the varying conditions of actual practical use.

Further objects and advantages of my invention will become apparent as the following description proceeds and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

2 For a better understanding of my inventio reference may be had'to the accompanying drawings in which Fig. 1 is a view partly in section of my fuseless cutout in the normal operative position;Fig. 2 is a similar view of the device after the circuit has been interrupted; Fig. 3 is a crosssectional view taken on line 3-3 of Fig. 1; Fig. 4 is a front view of the circuit breaker mounted on the door of the fuseiess cutout holder; Fig. 5 is a cross-sectional view of the circuit breaker in the operative position of Fig. 1; Fig. 6 is a view partly in section illustrating the device of my invention at one instant during the circuit-interrupting interval, and Fig. '1 represents one Step in the resetting of the fuseless cutout of my invention. V V

Referring now to the drawings, I have illustrated my invention in connection with a housing ID of porcelain or similar insulating material of the size and shape used in connection with the fuse cutouts of the prior art, such as is disclosed, for example, in United States Letters Patent 2,081,826, granted May 25, 1937, upon an application of George F. Lincks, and assigned to the same assignee as the present application. Housing i0 is preferably provided with an integrally formed electric creepage and gas barrier ll disposed between stationary line terminal contacts l2 and it carried by the housing. To the rear of the housing or casing I0 is secured a mounting bar H for the attachment of the casing to an electric line pole and cross-arm structure or the like. A pair of hinge brackets IE, only one of which can be seen in the drawings, are secured to the inner face of the rear wall of the casing adjacent the bottom thereof for engagement with e,- rod-shaped .pivot member l6 associated with the circuit-breaker assembly to be described hereinafter. biased jaws I51: and |5b between which pivot member l6 may readily be inserted but which provides good electrical contact at the hinge joint.

Contacts l2 and it are adapted .to have line conductors or leads fastened thereto by means of clamping screws l2 and ii, respectively, and upper contact I! has a contact finger I! backed up by means of a. spring strip l8 which serves to press the finger l1 downwardly and has also a pair of spaced resilient contact fingers it, only one of which can be seen in the drawings, backed up by' means of a spring strip 20. These contact fingers l9 are arranged to receive the terminal cap 2| of my improved circuit breaker which is simila to the terminal cap of the fuse holders Hinge brackets i5 comprise springto slide.

3 of the prior art. Contact I3 is electrically connected with pivot member l6 by virtue of jaws lid and |b of hinge bracket l5,

A door or cover 22 preferably constructed of insulating material is provided for housing In and suitably supports at 23 the door-mounted electric circuit breaker 24 to be described hereinafter. On the outer face of door or cover 22, there is formed an eyelet handle 25 which may be either grasped manually or engaged by a suitable switch stick 28, shown in Fig. 7, for interrupting the electric circuit as by swinging the door and associated circuit breake outwardly upon pivot member I8 held by the jaws |5a and lib of hinge brackets l5 or bodily removing door 22 from housing In. Door 22 is held in position in housing It by spring pressed contact fingers l1 and I9 which engage terminal cap 2| of the door-mounted circuit breaker 24 at the upper end thereof and jaws |5a and |5b of hinge brackets l5 which engage pivot member l8 of the door-mounted circuit breaker 24 at the bottom thereof.

In order that my fuseless cutout be compact and of substantially the same size as the fuse cutouts of the prior art, I provide a door-mounted circuit breaker 24 which comprises two electric circuits connected in parallel with one another. The first of these circuits comprises th main current-conducting path through which the power flow takes place under normal conditions. This path extends from terminal cap 2| which is threadedly supported by a conducting member 21 through a latching means 28, a pair of flexible conductors 29, a pair of main switching means 38 comprising relatively movable contacts 38a and 382), a pair of flexible connectors 3|, and a conducting slidable member 32 integrally connected with supporting pivot pin l6. Contacts 38a are stationary and are mounted to support 23 attached to door 22. Contacts b, on the other hand, are movable and are suitably fastened as by welding to an annular-shaped conductor 33, which is provided with an integrally connected hook 34 fo engaging with slidable member 32, as will be pointed out hereinafter, and an integrally mounted keeper for engagement with a roller 38 supported by latching means 28.

Relative movement, between contacts 30a and 30b is obtained by virtue of an energy-storage means comprising tension spring 31 connected between hook 34 and slidabl member 32 so as to bias movable contacts 38b away from stationary contacts 38a to interrupt the main current-carrying path through circuit breaker 24. The movement of contacts 38b is guided by means of insulating expulsion tube 38 described in greater detail hereinafter along which annular-shaped conductor 33 which encircles tube 38 is adapted Tube 38 is supported along with stationary contacts 300 by member 23 fixedly attached to door 22 and, in turn, supports conducting member 21 to which terminal cap 2| is attached.

When roller 36 of latching means 28 engages keeper 35, relatively movable contacts 30a and 30b of switching or isolating means 30 are held in conducting engagement. Any suitable means may be provided for releasing latching means 28 so that the energy-storage means comprising tension spring 31 causes separation of contacts 30a and 38b. Such means may comprise a magnetic trip or, as illustrated in the drawings, a thermalresponsive trip may be provided. Accordingly, I

have shown latching means 28 constructed as a bimetallic element through which substantially all the current flows when contacts 38a and 382) are in engagement. An abnormal current condition on the power line associated with my fuseless cutout will cause heating of bimetallic latching means 28 and consequent deflection thereof as shown in Figs. 2 and 6 so that roller 36 releases keeper 35 whereupon tension spring 31 causes separation of contacts 38a and 38b.

Manual means for tripping latching means 28 are provided in the form of a pair of hook-shaped fingers 38, suitably supported from the rear wall of housing III, which engage with extensions 48 of a pivot pin upon which roller 36 is mounted. If door 22 of housing I0 is opened fingers 38 engagin extensions 48 will cause deflection of latching means 28 so that roller 38 releases keeper 35, whereupon the energy stored in tension pring 31 is again released to cause separation of contacts 30a and 38b.

It will be understood by those skilled in the art that contacts 30a and 301), as shown, are not capable of satisfactorily interrupting large values of current at high voltage and, accordingly. I provide an additional circuit including relatively movable arcing contacts 4| and 42, Figs. 5 and 6, connected in parallel with the circuit including bimetallic latching means 28 and contacts 30a and 38b. These arcing contacts 4| and 42 are arranged to interrupt the circuit through circuit breaker 24 within expulsion tube 38 which is preferably constructed of an insulating material of the type from which arc-extinguishing gas is evolved under the influence of the heat of an electric arc. It will, of course, be understood by those skilled in the art that expulsion tube 38 may be constructed of ordinary insulating material and lined with a material of the gasevolving type. Arcing contacts 4| and 42 are preferably constructed of a suitable arc-resistant material, such as tungsten, for example.

Under normal conditions, it is desirable that substantially of the current flowing through circuit breaker 24 be carried by main current-carrying contacts 30a and 38b and bimetallic latching means 28 while very little current is carried by arcing contacts 4| and 42. In order to provide for this current division between the parallel conducting paths of circuit breaker 24, arcing contacts 4| and 42 may be connected in series with an impedance to current flow, such as a small gap, or, as illustrated in Fig. 5, with a resistance 43. This resistance 43 may comprise a block of carbon although, in order that the voltage across resistance 43 may be held to a low value regardless of the current passing therethrough, it is preferable that resistance 43 be constructed of a material having an inverse voltage resistance characteristic. One such resistance material is commercially available under the trade name Thyrite and is described and claimed in United States Letters Patent No. 1,822,742, granted September 8, 1931, upon an application of Karl B. McEachron. It will, of course, be understood by those skilled in the art that a resistance having a positive voltage resistance characteristic may also be employed even though not quite so satisfactory. In some cases, it may also be desirable to omit resistance 43 since an arcing rod 44 connected in series with arcing contact 42 may be provided of a material, such, for example, as stainless steel having a somewhat higher resistance than conducting materials, such as copper.

Arcing no u extends for the major length of expulsion tube 38 and is suitably connected to annular conducting ring 33 by a U-shaped con- 7 ducting member 45, best shown in Fig. 4. Arcing contact 4|, on the other hand. is electrically connected with terminal cap 2| by means of flexible conductor 46, see Figs. and 6, which, in turn,

is in conducting relationship with resistance 43.

rounded by suitable insulation 41 so that only A the ends thereof are in conducting relation with terminal cap 2| and flexible connection 45. A suitable compression spring 48 tends to bias contact 4| toward contact 42 until the full extent of flexible conductor 45 is. reached. Arcing contacts 4| and 42 are so constructed and arranged with respect to main current-carrying contacts 30a and lllbthat the latter are disengaged flrst so that all the current is transferred to the parallel circuit including arcing contacts 4| and 42. Thereafter, the circuit is interrupted in expulsion tube 38 and the arc drawn rapidly extinguished under the expulsion principle by virtue of the arc-quenching gases evolved from the walls of expulsion tube 38 or, if provided with a liner, from the liner.

Slidable member 32, to which is integrally mounted pivot pin I5, is constructed so as to engage a pair of grooves 48, Fig. 3, formed in a T-shaped extension 22a on the inner wall of door 22. This extension is also provided with a slot 58, see Fig. 3, through which hook 34 is adapted to slide. Slidable member 32 is provided with an extension 5| which encircles expulsion tube 38 and is slidable therealong and, furthermore, supports pivot pin it. This extension 5| is provided with slots 52 on either side thereof for guiding U-shaped conducting member 45 during circuit-interrupting operation and, at the same time, maintaining arcing rod 44 substantially in the center of expulsion tube 38. The T-shaped extension 22a on the inner wall of door 22 is provided with an abutment 53, see Fig.5, for holding slidable member 32 in the lower position so as to stress spring means 31 when main current carrying contacts 30:: and 30b are held in engagement by latching means 28. Hook 34 is constructed to engage slidable member 32 as shown in Fig. 2 to limit the downward movement of conducting ring 33 and associated movable contacts 38b.

It will be understood that ushaped conducting member 45 provides an indicating means to show the condition of the circuit breaker '24 of my fuseless cutout. When the circuit breaker is closed, as in Fig. 1, the U-shaped conducting member 45 is completely within casing or housing lfl whereas, if the circuit is open, as in Fig. 2, member 45 extends out of the bottom of housing Ill to indicate clearly to the lineman that the circuit is open.

The operation of my fuseless cutout will be briefly described with reference first to Figs. 1, I

4, and 5, where the circuit breaker 24 is shown in the closed-circuit position. Due to the higher resistance of the conducting path including arcing contacts 4| and 42 by virtue of the resistance of arcing rod 44 or resistance 43 if provided, substantially all the current passing through circuit breaker 24 is carried by bimetallic latching means 28 and main current-carrying contacts 30a and 30b. In the event of an abnormal current condition the resultant heating ofbimetallic latching means 28 will-cause a deflection thereof, as shown in Figs. 2 and 6, so that roller 35 releases keeper 35 and allows spring'means 31 to cause 5 separation of contacts 38a and 30b and eventually also 01' arcing contacts 4| and 42.

Due to the fact that spring" causes-arcing contact tofollow arcing contact 42 during the initial opening movement of circuit breaker 24,

loss shown in Fig. 6, contacts 30a and 301) are disengaged while arcing contacts 4| and 42 are still in engagement. The current which normally-flowed th'rough bimetallic latching means 28 and current-carrying'contacts 30a and 38b is, therefore, transferred to the parallel path including arcing contacts 4| and 42 and resistance 43. arcing contact 42 will cause an arc to be drawn between contacts 4| and 42 which will be rapidly 2o extinguished by the expulsive action of the arcquenching gases evolved from the walls of expulsion tube 38 under the influence oi the are drawn.

Arcing contacts 4| and 42 and main currentcarrying contacts a and 302) will be separated by a distance determined by the point at which hock 34 sliding in slot 50 engages with the upper edge of slidable member 32. Arcing rod 44 and associated U-shaped conductor 45 will extend 30 from the lower end of-housing ill in the opencircuit position of circuit breaker 24 so as to give a clear indication to the linemen of the condition of the fuseless cutout. This may clearly be observed by comparing Figs. 1 and 2. In Fig. l, arcing rod 44 and conductor 45 are completely contained within housing Ill whereas, in Fig. 2, they extend for a considerable distance outside of housing I 0.

In order to reset the circuit breaker after the circuit has been interrupted, as shown in Fig. 2.

the operator may employ a switch stick 25, as shown in Fig. '7, by means of which door 22 is pulled downwardly, to cause disengagement of terminal cap 2| and contact fingers I9, to the position shown in Fig. 7. This is possible by virtue of the fact that slidable member 32 'has'been caused to disengage from abutment 53 by the wedge-shaped portion of hook 34, best shown in Fig, 2. When the door 22 is pulled downwardly to the position shown in Fig. 7, current-carrying contacts 304: and 30b are engaged and the roller 35 of latching means 28 may reengage with keeper 35. Thereafter, door 22 is moved upwardly to cause slidable member 32 to move downwardly.

55 stressing spring means 31 until slidable member 32 reengages with abutment 53, whereupon door 22 is closed so that terminal cap 2| is again engaged by contact flngers I1 and I9 and the circuit is again completed through circuit breaker It will be observed that, with my circuit breaker. bimetallic latching means 28 carries the high current only during the heating period after which it trips and no longer carries any current. This is 05 particularly advantageous since, if there is an appreciable arcing time and the bimetallic latch carried the current during all this time; it might very likely be damaged or destroyed.

As will also be evident from the foregoing de- 7 scription, the present invention provides pronounced advantages over the fuse cutouts oi the prior art in that it is unnecessary to replace any parts before the circuit may again be completed after a circuit interruption, it being merely necessary for the linemen to reclose the circuit breaker Further movement of arcing rod 44 and in the manner described above. Furthermore, an indication of the condition or the iuseless cutout is at all times evident to the linemen.

While I have shown and described a particular embodiment of my invention for a fuseless cutout, I do not desire my invention to be limited to the construction shown and described for it will. of course, be obvious to those skilled in the art that changes and modifications may be made without departing from my invention and I, therefore, aim in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent 01 the United States is:

1. In an electric circuit interrupter, a pair of relatively movable current-carrying contacts, means for maintaining said contacts in currentconducting relationship, means for separating said contacts in response to abnormal current conditions, a relatively high-resistance path connected in parallel with said current-carrying contacts and said abnormal current responsive means including a pair of relatively movable arcing contacts, an expulsion tube within which said arcing contacts are arranged to separate, said currentcarrying contacts and said arcing contacts being so constructed and arranged that the former separate prior to the latter so that the current car-. ried by said current-carrying contacts is diverted to said relatively high-resistance path to be intersupted subsequently by said arcing contacts.

2. In an electric circuit interrupter, a pair of relatively movable current-carrying contacts,

means tending to bias at least one of said contacts to the open-circuit position, conducting means connected in series with said contacts for holding said contacts in current-conducting relacontacts, a bimetallic latch connected in series therewith for holding said contacts in conducting engagement and responsive to abnormal current conditions for releasing said spring to cause separatiton of said contacts, a relatively high-resistance path connected in parallel with said current-carrying contacts and said bimetallic latch including a pair of relatively movable arcing contacts, an expulsion tube within which said arcing contacts are arranged to separate, said currentcarrying contacts being arranged to separate prior to the separation of said arcing contacts so that the current carried thereby is diverted to said relatively high-resistance path to be interrupted in said expulsion tube by said arcing con- I tacts.

tionship, said last-mentioned means being responsive to abnormal current conditions for allowing separation of said contacts, a relatively high-resistance path connected in parallel with said serially connected current-carrying contacts and said last-mentioned means including a pair of relatively movable arcing contacts, said ourrent-carrying contacts being arranged to separate prior to the separation or said arcing contacts so that the current carried thereby is diverted to said relatively high-resistance path to be interrupted by said arcing contacts.

3. In an'electric circuit interrupter, an expulsion tube, a pair of relatively movable arcing contacts mounted therein, a conducting path connected in parallel with said arcing contacts for carrying substantially all the current flowing through said circuit interrupter under normal current conditions comprising a pair of relatively movable current-carrying contacts and latching means for holding said current-carrying contacts in engagement, said latching means being releasable in response to abnormal current conditions,

a means connected in series with said arcing contacts for causing substantially all the current carried by said circuit breaker to flow through said parallel conducting path when said current-carrying contacts are in engagement, means for causing separation of said current-carrying contacts upon release of said latching means to divert said current from said conducting path'to said arcing contacts, and means for causing subsequent separation of said arcing contacts to interrupt the circuit in said expulsion tube.

4. In an electric circuit interrupter, a pair of relatively movable current-carrying contacts, spring means tending tocause separation of said 5. In a circuit interrupter, the combination of a housing comprising a casing and a door for closing an open side of said casing, an electric circuit breaker mounted on said door and comprising a pair of relatively movable current-carrying contacts, means for maintaining said contacts in current-conducting relationship, means for separating said contacts in response to obnormal current conditions, a relatively high-resistance path connected in parallel with said ourrent-carrying contacts and said abnormal current responsive means including a pair of relatively movable arcing contacts, said current-carrying contacts being arranged to separate prior to the separation 01' said arcing contacts so that the current carried thereby is diverted to said relatively high-resistance path to be interrupted by said arcing contacts and means dependent upon the opening of said door for eflecting the closure of said current carrying contacts.

6. In a load-disconnecting device, the combination of a casing and a door for closing on open side of said casing, a circuit interrupter mounted on said door comprising a pair of relatively movable contacts, latching means for holding said contacts in current-carrying relationship, and means for causing release of said latching means upon openin the door of said casing.

'7. In an electric circuit interrupter, the combination of a casing and a door for closing an open side of said casing, a circuit breaker mounted on said door comprising a pair of relatively movable current-carrying contacts, means for maintaining said contacts in current-conducting relationship, means for separating said contacts in response to abnormal current conditions, a current-conducting path in parallel with said current-carrying contacts including a pair of relatively movable arcing contacts, an expulsion tube within which said arcing contacts are arranged to separate, and means for tripping said first-mentioned means upon opening the door of said casing for interrupting the circuit through said circuit breaker.

8. In an electric circuit interrupter, the combination of a casing and a door for closing an open side of said casing, a circuit breaker moimted on said door comprising a pair of relatively mowable current-carrying contacts, means for maintaining said contacts in current-conducting relationship, means for separating said contacts in response to abnormal current conditions, a relatively high resistance path connected in parallel with said current-carrying contacts including a pair of relatively movable arcing contacts, an expulsion tube within which said arcing contacts are arranged to separate, said currentfcarrying contacts and said arcing contacts being so constructed and arranged that the former separate prior to the latter so subsequently by said arcing contacts, and means I for tripping said first-mentioned means upon opening the door of said casing for causing in.-

, terruption oi the circuit through said circuit breaker. r v

9. In a load-disconnecting device, the combination of a casing and a door for closing an open side otlsaid casing, a circuit interrupter mounted on said door including an expulsion tube and a pair or relatively'movable arcing contacts'mount ed therein, means for causing interruption of said circuit in said expulsion tube upon opening the door of said casing.

10. In a load-disconnecting device or the type including a casing with a door for closing an open side of said casing, an electric circuit interrupter mounted on said door, means for resetting said circuit interrupter after circuit interruption thereby merely by moving said door first in one direction and then in the other.

11. In 'a circuit interrupter, the combination oi a casing and a door for closing an open side of said casing, an" electric circuit breaker mounted on said door comprising a -pair, of relatively movable current-carrying contacts, means for 10 path 'upon release oi said bimetallic latch so that said bimetallic latch is immediately relieved from carrying the abnormal current upon separation of said current-carrying contacts. Y 14. -In an electrlc'circuit interrupter adapted for use in place oi conventional fuse cutouts, the combination of a casing and a cover for closing an open side of said. casing, a circuit interrupter mounted on said cover comprisinga pair of relatively movable contacts, means for causing rela. tive separation of said contacts to interrupt the circuit-associated'with said circuit interrupter, and means dependent upon the opening of said cover for effecting the closure of said contacts.

15. In an electric circuit interrupter adapted for use in place of conventional fuse cutouts," the combination of a casing and a cover for closin an open side 01' said casing, a circuit interrupter mounted on said cover comprising-a pair of relatively movable contacts, bimetallic means for ini tiating relative separation of said contacts to interrupt the circuit associated with said circuit interrupter, and means dependent upon the opening and closing of said cover to re-establish an electric circuit through said contacts.

16. In an electric circuit interrupter, the combination of a casing and a cover for closing an maintaining said contacts in current-conducting relationship, means for separating said contacts in responseto abnormal current conditions, and expulsion type interrupter connected in parallel with said current-carrying contacts and said abnormal current responsive means and means dependent upon the opening and closing of said door for reclosing said contacts to re-establish an electric circuit therethrough.

12. In a circuit interrupter, the combination of a casing and a door for closing an open side of said casing, an electric circuit breaker mounted on said door comprising a pair of relatively movable current-carrying contacts; Hatching means for maintaining said contacts in currentconducting relationship, said latching means being responsive to abnormal current conditions, means for separating said contacts upon release of said latching' means, a conducting path connected in parallel with said latching means and said current-carrying contacts including a pair of relatively movable arcing contacts connected in series with a rod formed of a materialfurnishing a higher impedance to the current flowing through said circuit breaker. than the circuit through said current-carrying contacts, said rod being arranged to extend out 01' said casing upon circuit interruption to indicate the condition of said circuit interrupter. v

13. In an electric circuit interrupter, a pair oi relatively movable current-carrying contacts, spring means tending to cause separation of said contacts, a bimetallic latch responsive to abnornial current conditions connected in series with said contacts for holding them in current-conducting engagement under normal current conditions and permitting said spring means to become effective under abnormal current conditions, a current-conducting path connected in parallel with said currentcarrying contacts and said bimetallic latch including a pair of relatively movable arcing contacts, means for causing said current-carrying contacts and said bimetallic latch to carry substantially all of the current flowing through said circuit'breaker'under norranged that said contacts may be reclosed to reestablish an electric circuit therethrough by place of conventional fuse cutouts the combinamal current conditions, means for causing the current to be divertedto said parallel conducting open side of said casing, a circuit breaker mounted on said cover comprising a pair of relatively movable contacts, and means for causing relative separation of said contacts to interrupt the circuit associated with said circuit breaker, said circuit breaker being so constructed and armovement of the cover of said casing.

17. In an electric circuit interrupter, the combination of a casing and a cover for closing an open side of said casing, a circuit breaker mount,-

circuit breaker being so constructed and -ar-.

ranged that said contacts may be reclosed to reestablish an electric circuit therethrough by bodily movement of said circuit breaker.

18. In a circuit interrupter adapted for use in place of conventional fuse cutouts the combination of a casing and a cover for closing an open side of said casing, an electric circuit breaker mounted on said cover comprising a pair of relativelymovable current carrying contacts, means for maintaining said current carrying contacts in current conducting relationship, arcing contacts associated with said current carryingcontacts, means electrically connected in parallel with said arcing contacts for first causing separation of said current carrying contacts and then said arcing contacts in response to an abnormal current condition, and means dependent upon the opening and closing of said cover for reclosing said current carrying contacts to re-establish an electric circuit therethrough.

19. In a circuit interrupter adapted for use in tion of a supporting insulator, a support ior an electric circuit breaker mounted on said insulator and movable relative thereto, said circuit breaker comprising a pair of relatively movable current carrying contacts, means form'aintaining said current carrying contacts in current conducting relationship, arcing contacts associated with said current carrying contacts, means electrically connected in parallel with said arcing contacts for first separating said current, carrying contacts and then said arcing contacts in response to an abnormal current condition, and means dependent upon movement of said support for effecting the closure of said current carrying contacts.

20. In a circuit interrupter, the combination of a casing and a cover for closing an open side of said casing, an electric circuit breaker mounted on said cover comprising a pair of relatively movable current carrying contacts, means for maintaining said contacts in current conducting relationship, means for separating said contacts in response to an abnormal current condition, arcing contacts associated with said current carrying contacts, and means for reestablishing the circuit through said current carrying contacts by movement of the cover of said casing.

21. In an electric circuit interrupter, the combination of a casing and a cover for closing an open side of said casing, a circuit breaker mounted on said cover comprising a pair of relatively movable current carrying contacts, means for maintaining said current carrying contacts in current conducting relationship, means for separating said current carrying contacts in response to an abnormal current condition, arcing contacts associated with said current carrying contacts, and means for operating said first mentioned means to permit separation of said areing contacts upon opening the cover of said casing for interrupting the circuit through said circuit breaker.

22. In a circuit interrupter adapted for use in place of conventional fuse cutouts the combination of a casing, line terminals in said casing, a cover for closing an open side of said casing, an electric circuit breaker mounted on said cover and movable into and 'out of engagement with at least one of said line terminals in said casing, said electric circuit breaker comprising a pair of relatively movable current carrying contacts, means for maintaining said current carrying contacts in current conducting relationship, circuit interrupting means associated with said current carrying contacts, means electrically connected in parallel with said interruptins means for separating said current carrying contacts in response to abnormal current conditions to interrupt the circuit associated with said circuit interrupter, and means dependent upon the opening and closing of said cover for reclosin said current carrying contacts to re-establish an electric circuit therethrough.

23. In a circuit interrupting device, a pair of I spaced terminals, bridging means normally electrically connecting said terminals and movable into and out of engagement with at least one of said terminals, means latchnig said bridging means to said one terminal to normally hold said bridging means in the closed circuit position, separable contacts carried by said bridging means biased to open circuit position, means for latching said separable contacts in the closed circuit position, and means responsive to one continuous movement ofsaid bridging member 101- first unlatching said separable contact latching means and then unlatching said bridging means from said one terminal to permit the bridging means to be .moved out of engagement with said one terminal.

24. In a circuit interrupting device, a pair of spaced terminals, bridging means nounally electrically connecting said terminals and movable into and out of engagement with at least one o;

. 12 said terminals. means latching said bridging means to said one terminal to normally hold said bridging means in the closed circuit position, separable contacts carried by said bridging means biased to open circuit position, means for latching said separable contacts in the closed circuit position, means responsive to one continuous movement of said bridging member for first unlatching said separable contact latching means and then unlatching said bridging means from said one terminal to permit the bridging means to be moved out of engagement with said one terminal, and means operable in response to movement of said bridging means to the open position for latching said separable contacts in the closed circuit position.

25. In a circuit interrupting device, a pair of disconnecting contacts, one of which is mounted on a movable contact support for movement therewith into and out of engagement with its cooperating contact, current interrupting contacts carried at all times by said movable support and connected in series with said disconnecting contacts, an operating mechanism for sequentially operating said contacts in acircuit opening operation to first open said interrupting contacts and to thereafter open said disconnecting contacts, and means operable to automatically open said current interrupting contacts independently or movement of said dlsconnecn ing contacts in response to currents above a predetermined value.

26. In a circuit interrupting device, a pair of disconnecting contacts, one of which is mounted on a movable contact support for movement therewith into and out of engagement with its cooperating contact, current interrupting contacts carried at all times by said movable support and connected in series with said disconnecting contacts, means for sequentially operating said contacts in both a circuit closing and a circuit opening operation, and additional means for automatically opening said current interrupting contacts independently of movement of said disconnecting contacts in response to the passage through the device of currents greater-than a predetermined magnitude.

27, In a circuit interrupting device, a pair of disconnecting contacts, one of which is mounted on a movable contact support for movement therewith into and out 01' engagement with its cooperating contact, current interrupting contacts carried at all times by said movable support and connected in series with said disconnecting contacts, snap-acting means for operating said current interrupting contacts, means for sequentially operating said snap-acting means and said movable support to seque t ly ope a said current interrupting contacts and said disconnecting contacts, and means for causing antomatic operation of said snap-acting means to open said current interrupting contacts independently of movement or said disconnecting contacts in response to the passage through the device of currents above a predetermined value.

28. In a circuit interrupter, an arc extinguishing device mounted for bodily movement, a pair of disconnecting contacts, one of said disconnecting contacts being movable with said are extinguishing device into and out of engagement with the other of said disconnecting contacts, a pair of arc establishing contacts both of which are supported at all times by said are extinguishing device and connected in series with said disconnecting contacts, operating means for both or said are extinguishing device to open the circuit at said disconnecting contacts, and means operable to cause said operating means to automatically open said are establishing contacts independently of movement of said disconnecting contacts in response to passage through the interrupter of currents above a predetermined magnitude.

29. In a circuit interrupter, an arc extinguishing device mounted for bodily movement, a pair of disconnecting contacts, one of said disconnecting contacts being movable with said are extinguishing device into and out of engagement with the other of said disconnecting contacts, said are extinguishing device having a pair of arc establishing contacts connected in series with said disconnecting contacts, means responsive to the opening movement of said movable disconnecting contact for sequentially opening said are establishing contacts and said disconnecting contacts and to the closing movement of said movable disconnecting contact for sequentially closing said are establishing contacts and'said 'dis connecting contacts, and means independent of the movement of said movable disconnecting contact for opening said are establishingcontacts.

30. In an interrupter, a pair of spaced terminals, a hollow switch member for bridging said terminals, said bridging member having a contact thereon engageable with one of said terminals, circuit interrupter means in said hollow switch member connected to the other terminal and said contact and operable to interrupt a circuit between said terminals when said switch member is in bridging position, means responsive to one continuous movement of said bridging member to first open said interruptingcontacts and then swing said switch member to open position, and means operable in response to predetermined conditions to cause said mechanism to automatically open said interrupting contacts.

31. In a circuit interrupting device, a movably mounted enclosure, a pair of disconnecting contacts, one of which is movable with said enclosure into and out of engagement with the other of said disconnecting contacts, are establishing contacts within said enclosure and connected in series with said disconnecting contacts, operating means responsive to one continuous movement of said enclosure for sequentially operating said contacts and including means on said enclosure operable in response to the passage therethrough of currents abov a predetermined magnitude to open at least said arc establishing contacts.

32. In a circuit interrupting device, a movably mounted tubular ,arc extinguishing device, a pair of disconnecting contacts one of which is movable with said arc extinguishing device into and out of engagement with the other of said disconnecting contacts, are establishing contacts within said are extinguishing device and connected in series with said disconnecting contacts, operating means responsive to one continuous movement of said are extinguishing device for sequentially operating said contacts and including means operable in response to the passage therethrough of currents above a predetermined magnitude to open at least 'said are establishing contacts.

33. In a circuit interrupter, an arc extinguishing device mounted for bodily movement, a pair of disconnecting contacts, one of said disconnecting contacts being movable with said are extinguishing device into and out of engagement with the other of said disconnecting contacts, said are extinguishing device having a pair 01' are establishing contacts connected in series with said disconnecting contacts, means responsive to the opening movement oi said movable disconnectin8 contact for sequentially opening said are establishing contacts and said disconnecting contacts and to the closing movement of said movable disconnecting contact for sequentially closing said are establishing contacts and said disconnecting contacts, and current responsive means for opening said arc establishing contacts independently of the movement of said disconnecting contacts, whereby said are establishing contacts may be opened by said current responsive means while said disconnecting contacts are closed.

34. In a circuit interrupting device, insulating support means, a pair of disconnecting contacts mounted on said support means, one or said contacts being mounted for movement into and out of engagement with the other to insert a large visible air gap in the circuit when in open position. current interrupting contacts also mounted on said support means and arranged in series circuit relation with said disconnecting contact, an operating mechanism operable in response to movement of said movable disconnecting contact for sequentially operating said contacts in a circuit opening operation to first open said interrupting contacts and to thereafter open said disconnecting contacts, and means operable to automatically open said current interrupting contacts in response to currents above a predetermined value.

35. In a circuit interrupting device, insulating support means, a pair of disconnecting contacts mounted on said support means, one of said contacts being mounted for movement into and out of engagement with the other to insert a large visible air gap in the circuit when in open posi- I tion, current interrupting contacts also mounted on said support means and arranged in series circuit relation with said disconnecting contacts, means responsive to movement or said movable disconnecting contact for sequentially operating said contacts in both a circuit closing and a circuit opening operation, and additional means for automatically opening said current interrupting contacts in response to the passage through the device of currents greater than a predetermined magnitude.

36. In a circuit interrupting device, insulating support means, a pair of disconnecting contacts mounted on said support means, one of said contacts being mounted for movement into and out of engagement with the other to insert a large visible air gap in the circuit when in open position, current interrupting contacts also mounted on said support means and arranged in series mounted on said support means, one of said contacts being mounted for movement into and out of engagement with the other to insert a large visible air gap in the circuit when in open position, current interrupting contacts also mounted on said support means and arranged in series circuit relation with said disconnecting contacts, common operating means for said disconnecting and interrupting contacts including means responsive to the opening movement of said movable disconnecting contact for sequentially opening said current interrupting contacts and said disconnecting contacts and to the closing movement of said movable disconnecting contact for sequentially closing said current interrupting contacts and said disconnecting contacts, and means independent of movement of said movable disconnecting contact for opening said current interrupting contacts.

38. In a circuit interrupting device, insulating support means, a pair of disconnecting contacts mounted on said support means, one of said contacts being mounted for movement into and out of engagement with the other to insert a large visible air gap in the circuit when in open position, current interrupting contacts also mounted on said support means and arranged in series circuit relation with said disconnecting contacts, common operating means for said disconnecting and interrupting contacts including means responsive to the opening movement of said movable disconnecting contact for sequentially opening said current interrupting contacts and said disconnecting contacts and to the closing movement of said movable disconnecting contact for sequentially closing said current interrupting contacts and said disconnecting contacts, and current responsive means for opening said are establishing contacts independently of the movement of said disconnecting contacts, whereby said are establishing contacts may be opened by said current responsive means while said disconnecting contacts are closed.

39. In a circuit breaker adapted for use in place of conventional fuse cutouts the combination of a. casing and a cover for closing an open side of said casing, an electric circuit breaker mounted on said cover comprising a pair of relatively movable current carrying contacts, means for maintaining said contacts in current conducting relationship, arcing contacts associated with said current carrying contacts, means electrically connected in parallel with said arcing contacts for first separating said current carrying and then said arcing contacts in response to abnormal current conditions, and means dependent upon the opening and closing of said cover for reclosing said contacts to re-establish an electric current therethrough.

SIDNEY B. SMITH, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,838,664 Dubilier Dec. 29, 1931 1,964,093 Sperry June 26, 1934 Y 2,047,365 Fox July 14, 1936 2,081,814 Hermann May 25, 1937 2,239,829 Pittman et a1. Apr. 29, 1941 2,273,764 Salter Feb. 17, 1942 1,940,203 Bowie Dec. 19, 1933 2,272,717 Ludwig Feb. 10, 1942 2,301,746 Parker Nov. 10, 1942 2,401,656 Mosley June 4, 1946 2,082,028 Rawlins June 1, 1937 2,159,884 Crabbs May 23, 1939 2,223,731 Lingal Dec. 3, 1940 2,261,020 Crabbs Oct. 28, 1941 2,114,745 McCluskey et a1. Apr. 19, 1938 724,228 Wood Mar. 31, 1903 1,763,027 Wilms June 10, 1930 2,203,928 Schultz June 11, 1940 FOREIGN PATENTS Number Country Date 172,658 Great Britain Mar. 2, 1922 

